Process of coking oils



June 24, 1930. W L El AL PROCESS or comm} on'ls Original Filed April 8. l922 3 Sheets-Sheet 1 QNw WW WW UMMEL RWELLLR OLQLHS L\ rm flvwe ntots June 24, 1930. WELLER ET'AL 1,767,331

' PROCESS OF COKING OILS I Original Filed April 8. 1922 3 Sheets-$heet 2 FIG. (5

June 24, 1930. WELLER Er AL 1,767,331

PROCESS OF COKING OILS Original Filed April 8, 1922 3 Sheets-Sheet 3 DAPHEL. P\.WE\ LF.P-

AND Lows LANA 331 flbl'omut I awuewtw Patented June 24, 1930 8 UNITED 1 ST T 511sv iiactaur oFFicE DANIEL n. WELLER Am) LOUIS INK, 0 BATON ROUGE, LOUISIANA, nssieivons ro r STANDARD OIL DEVELOPMENT COMPANYQA CORPORATION OF DELAWARE rEocEss or GOKING oILs- Original application'filed April 8,1922, Serial No. 550,731, and in Canada June 6, 1924. Divided and this I application filed September 18, 1925; S.eria1-No.-57,078.

The present invention relates to the distil lation of petroleum oils, and more particularly to the dry or coking distillation of such oils-with fractional separation of the distillate constituents; p I

Thisapplication is a division of our prior application Serial No. 5507 31, filed April 8,

This invent-ion will be fully understood trom the following description,illustrated by 1 the accompanying drawings, in which:

Figure 1 is an elevation of the distillation and overhead equipment suitable for. carrying out the present invention,the overhead equipment being shown in part diagrammatically 7 2 is a plan view of the end of the still, showing the dome;

Figs. 3 and 4 are sect onal views showing the construction andarrangement of the condensing and fractionating towers;

Fig. 5 IS a side elevation of one end of the 7 still showing the dome in section; and

Fig. 6 is an elevation of a modified equipmentfor carrying out the invention, shown in part diagrammatically.

Referring more particularly to the form of construction of Fig. 1 of the drawings, the numeral 5 indicates a coking still mounted upon a suitable furnace setting6; A charge ing line 7 serves for the introduction of oil into the still. Near oneend the still is pro vided at its top with an enlarged dome .8, which may suitably be a dome of generally cylindrical shape. From near the top of the dome vapor outlets 9 are provided, there being two in the construction illustrated. The cross sectional area of the dome 8 and of the outlets 9 are such as to permit the vapors evolved in the still to be'taken off substane tially as fast as formed when therate of formation is such as to'completely eliminate all of the volatilizable constituents of the oil in from 10 to 18 hours. The outlets, may suitably be th the diameter of the dome, or

larger. With'a cylindrical still of the usual the still. Thuswith a'sti1l of approximately 14 feet in diameter and 40 feet in length, capable of receiving a charge of from/i0 to 50,000 gallons, the dome 8 may suitably be about six feet in diameter and the vapor pipes 9 each twelve inches in diameter.

The internalcons truction of the dome is illustrated most clearly in-the sectional view thereof in Figure 5. Below the openings 10 of the vapor pipes 9 an inverted frustro-conical deflector 11 is secured to the wall of the dome. Somewhat below this is mounted a pan 12, the deflector and pan being so arranged that any condensateforming on the walls of thedome is deflected into the pan12. From the pan 12 an outlet pipe 12 leads to the connection to the slop worm and wax line,

as hereinafter more fully pointed out. a

f From the dome the vapor'pipes 9 lead throughlines13 of about the lsamesize as the vapor pipes to a series of fractionating andco'ndensing towers, the arrangement of which is in general substantially thesame as that. describedin our Patent No. 1,609,007 '1 in the base of the secondtubularcondenser 19,

the construction of'which is substantially similar to that of tower l4]. Condensate from the chamber 15.ot tower 14 discharges through pipe 20 andcondensate from tubes 16 is collected in apan 21 and discharged through pipe22. Suitable connections are provided so that the cuts discharged through these pipes may be conducted individuallyor to gether through line 23 to cooling worm 24: or through line'25 to line 26 connecting with cooling worm 24; or'to line 2'? connecting with cooling worm 28; or through line'31 to wax line -29, or to the run-backiline 31 The'entire condensate formedin the tower 19 is discharged through pipe 32, which is provided with connections so-that the condensate may be divertedthrough line 33 into cooling worm 34 or into the run-back 35. Fromcondenser19 uncondensed vapors pass through densate formed in the condenser 37 is dischargedthrough pipe 42, which is provided with suitable connections whereby the condensate may be conducted through pipe 43 to condenser worm 44 or through run-back lin'e 45to the still.

The vapors passing out of the condenser 37 through pipe 41 enter the basepf a fourth condenser 46', which suitably be of the radiator type. Uncondensed vapors pass out of the condenser 46 through pipe 47 to the condenser worm 48. Condensate formed in condenser 46 is discharged through pipe 49 and connections are provided so "that it may be conducted back to the still through runback line 50 or through pipe 51 to cooling worm 52.

A portion of the vapors -from tower 37 may pass flout through pipe 41 into cooling coil 53. v The arrangement Ofcond'ensers and con nections permits of the greatest flexibility in the operation of the still,the mode of handling thedist'illates being substantially that of my prior application above referred to.

. In operating in accordance with the present invention, however, the 'hea'tingof the charge may be carriedout at a ratesuc'h as to reduce the time required for eiieciting'coking of the oil treated by one-third to one-half. It has hitherto been necessary iii-distilling oils to carefully fire the still so that the coking process, from the firing of the still to the completion of the coking process requires from 24 to 48 hours, the time depending upon the type of crude.

In the prior processes, when the temperature of the still reached s ay, 680 to 720 F.-, the greatly increased evolution of vapors made it necessary to =s1ow down the rate of distillation and reduce the firesve'ry considerably and in consequence of this, the cracking period was materiallyextended and the destruction of valuable wax-bearing vis cous distillate increased.

In accordance with the present process the heating of the still is so conducted that less than 18 hours is required fromthe time of firing to the coking of the still. Thus "with light Mexican crude oil it has been found convenientto carry outthe run from firingto coking in 15 to 18 hours and for oils such as Mid-Continent crude and Homer crude, in from 12 to 15 hours. The vapors evolved during the period following the reaching of a temperature of 680 to 720 F. pass freely through the system.

. The results of the runs'i'n accordance With this process present several characteristic differences from runs made under the longer schedule made necessary by the use of stills of the character hitherto in use, the size and capacity of the stills and the overhead equipment being identical in the comparative runs under the two types of schedules. The proportions and the character of the light products (naphtha, burning oil, and re-run distillate) are substantially the same. in the two types of processes. With respect to parafiin d is tillate,; by the present process a greater yield is produced when oils of the same viscosity are compared, or tor equal yields of pa'raiiin distillate, that :produced by the present processhas a better viscosity and a better cold test. The 'col're produced by the present process is materially less in quantity (about 10%) and, notwithstanding the more rapid heating of the-still, less of is burned to the bottom of the still. It has been noted with respect to the present process that the process yielded 18.36% of naphtha of 57.8

gravity- 34.11% of re-run distillate of 39.? gravity; 25.29% of pmain distillate of 26 1 gravity having a viscosity of 74 Saybolt 8.24%"o'ta p'a'raiiln slop having a gravity of 18.3 and a viscosity of 27 9 Saybolt; 12.09% of coke and 1. 91%lo's"s as wax ta il ings and as. .1. a Homer crude, run from firing to coking in about 13 hours and 30 minutes, yielded 31.39% of 61 Baum naphtha; 9.07% of 42f6fburi1ing "oil distillate 28.89% of re-run dramas of 33.9;9 gravity; 24.91% para'flin distillate having a viscosity of '80 Say-bolt; 2.16% of paraflin'slop'ot 18;3 Bauni ;2.33% of-coke-and 1.25% loss. I

Mid-Continent crud-e, run 'from firing to coking in about 14 hours and 30 minutes, yielding25.18% of 5'5i6 naphtha; 14.28% of 421 burningoil'distillate;"29.06% ot'39 rerun cl-is'tilla-te; 24.27% of p'araflin distillate of 271 gravity and '92 Saybdlt viscosity; 3.63% 0*]? -pa'rah'in'sl0p of 175 gravity; 235 of coke and 1.23% loss.

A generally more effective arr-angementof apparatus is illustrated in Fig.6 oft he draw'vings. The numeral 60 indicates a still, which may be charged thrdugh line 61 and is provided with'adome 33, the relative dimensions of the still and the dome and the construction of *the latter *being substantially the same as inth'e form-of apparatus previously described. The vaporsrrom the still pass outofthe dbme 63 thrpugh lines 64, each'ha-ving atfleast the diameter of the dome. From-'th'ese lines the vapors 'pass iii-to a -tower 65, the construction of which is substantially simfla'rto't-hat of'tdwer'14,-shbwi1in Fig. 40f

the drawing. Condensate fromthe tubes of tower passes out through lines 66 and condensate from the base chamber of this tower passes out through line 67. Either or both of these condensates may be directed into line 68 or line 69. Line 68 conveys the condensate passing through it directly to worm 70. From line 69 connectionsarevmade through line 1 with worm 70, through line 72 directly to worm 7 3, or through line 76 directly to wax line 75. Line 69 also connects with run-back line 69 The vapors from tower 65 pass out through at least two lines 77 into the base of tower 78, which is substantially similar to tower 65 except that the condensate from the tubes is discharged together with the condensate from the base of the chamber through pipe 79. From pipe 7 9 the condensate fromthe tower 78 passes either into run-back line I 80 or through line 81 intocooling worm 82.

The vapors passing out of tower 78are conveyed through at least two pipes 83, 83, into the base of tower 84, the construction of which is essentially similar to that of tower 37. Con densate from this tower isdischarged through line 85 either into run-back line 86 or into the line 87*, which conveys it to the cooling worm 88 The vapors uncondensed in tower 84: pass out through at least two vapor lines, 86, into the base of tower 87, the construction of which is substantially the same as that of tower 7 8. The condensate from tower 87 is discharged through line 88, from which it passes into run-back line 89 or through line 90 into cooling worm 91. The vapors passing through tower 87 are discharged through lines 92 and 92*. Line 92 discharges directly into condensing worm 93 and line 92 into condensing worm 94:.

In running, particularly with the second form of equipment, during the period prior to that in which paraflin distillate is being given off, a thorough and adequate separation of vapors is efiected in the towers aided by the running back of heavier condensates to the still and their redistillation. A. clean separation of the lighter fractions is consequently effected. During the period in which parafiin distillate or wax-bearing viscous fractions are being given off, only the condensate in tower 87, discharging through line 88, need be run back to the still, as each of the three preceding towers yields parafiin distillate whereas the condensate in the fourth tower may contain admixed gasoil and refined distillate. WVith the second form of equipment illustrated, in the case of light Mexican crude oil, for example, the length of the run from firing to coking may be shortened from 20 minutes to one hour and the yield of paraffin distillate increased from 2 to 5% over the yields secured by the first described form of equipment. o

Although the present inventlon has been described in connection with the specific details of an embodiment thereof, it is not intended that these details shall be regarded as limitations upon the scope of the invention, except in so far as included in the accompanying claims.

We claim:

1. The process I of running crude oil to coke which comprises confining the oil in a container, firing the container gradually until a temperature of 680 to720 F. is attained and paraflin distillate is formed, and continuing thedistillation at a rate such that the vaporizableportion of theoil is substantially completely vaporized in not less than 10 and not more than 18 hours and drawing 01f and fractionally condensing the vapors substantially as rapidly as formed.

2. The process of running crude oil to coke which comprises confining the oil in a container, applying heat to the container at a rate such that the vaporizable portion of the i 7 3. The process of running crude oil to I V coke which comprises confining the oil in a container, the charge of 011 beingin the order of forty thousand gallons, applying heat to the container at a rate such that the vaporizable portion of the oil is substantially vaporized in not. less than 10 and not more than 18 hours, drawing ofi andfractionally condensing the vapors substantially as rapidly as formed, and segregatinga plurality of fractions including naphtha, kerosene and parafin distillate. v

- DANIEL B. WELLER.

LOUIS LINK. f 

